(1) Field of the Invention
The present invention relates to a semiconductor device, and more specifically, it relates to a semiconductor device having an anti-fuse, in which a dielectric breakdown of the anti-fuse makes it conductive to perform a storage of information.
(2) Description of the Prior Art
Recently, an anti-fuse has often been used as a component of a memory cell of a PROM or as an element for closing a circuit (e.g., "Dielectric Based Anti-fuse for Logic and Memory IC", IEDM 88, pp 786-789). The anti-fuse includes an insulating film and electrodes holding it therebetween, and the anti-fuse is subjected to a dielectric breakdown to become irreversibly conductive when a specified programming voltage V.sub.p is applied between the electrodes. This enables the memory cell of the PROM to store information (program), and it also leads to a closing of the circuit.
There are some known anti-fuse elements; for example, U.S. Pat. No. 4,899,205 discloses an anti-fuse element under the title of "ELECTRICALLY-PROGRAMMABLE LOW-IMPEDANCE ANTI-FUSE ELEMENT".
An ordinary operating voltage (supply voltage) V.sub.cc is set to a value smaller than the programming voltage V.sub.p so that the anti-fuse is not broken down in the programming and may not be broken down during the PROM (Programmable Read Only Memory) reading operation or during the operation of the circuit. For this reason, conventionally, there arises the problem that in programming the programming voltage V.sub.p must be supplied from the outside.
Accordingly, it is an object of the present invention to provide a semiconductor device capable of storing information without supplying the programming voltage from the outside in some way.